This disclosure relates to corrosion inhibitors and, more particularly, to a corrosion inhibitor that is effective for use on aluminum alloys having relatively high amounts of zinc.
Components made from metallic alloys, such as aluminum alloys, achieve higher strengths through inclusion of alloying elements. However, the presence of these alloying elements tends to make the alloy vulnerable to corrosion. Typically, the component utilizes a protective coating containing a corrosion-inhibitor to protect the underlying alloy from corrosion.
One type of corrosion-inhibitor includes hexavalent chromium in the form of a barium or strontium chromate compound, for example. Although effective, hexavalent chromium is commonly recognized as a carcinogen and is therefore undesirable for use as a coating.
Chrome-free corrosion-inhibitors have been used as an alternative to hexavalent chromium inhibitors. For example, chrome-free corrosion inhibitors utilize anodic and cathodic corrosion inhibitors to resist corrosion of the underlying alloy. One drawback of existing chrome-free corrosion inhibitors is that they do not provide equal corrosion protection for all alloy compositions.
New compositions of aluminum alloys are being developed and are finding use in industries such as the aerospace industry. Although conventional corrosion inhibitors, such as EcoTuff®, have been effective in providing corrosion protection, an even greater degree of corrosion protection is desired. Accordingly, there is a need for a corrosion-inhibiting substance that provides enhanced corrosion protection of aluminum alloys.